Avalanche Forecast
Issued: Feb 23rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
zryan,
Avalanche Canada
Wind slabs are the main concern. Keep in mind you may find them on a variety of aspects with recent shifting winds.
Sheltered terrain will offer the best and safest riding.
Summary
Confidence
Avalanche Summary
On Thursday, skiers were able to trigger small (size 1) isolated pockets of stiff wind slab in alpine through to below treeline terrain.
Most recent avalanche activity has been reported as size 1-1.5 wind slabs and storm slabs in the alpine, mainly formed by recent northerly winds.
Snowpack Summary
Northerly winds have redistributed new snow and formed stiff wind slabs in exposed areas. In sheltered areas, surface faceting due to cold temperatures and/or soft surface snow remains.
There are two crusts with facets sitting above, which are buried in the snowpack down 60-180cm in the alpine and treeline elevation bands. These crust/facet layers have been responsible for several large avalanches in the past 2 weeks in the Brandywine and Pemberton Icefield areas.
Weather Summary
Thursday night
Clear. Alpine temperatures around -23 °C. Ridge wind northeast 15 km/h. Freezing level at valley bottom.
Friday
Sunny with cloudy periods. Alpine temperatures reach a high of -13 °C. Light variable ridge wind. Freezing level at valley bottom.
Saturday
Cloudy with snowfall beginning in the afternoon, 5 cm of accumulation. Alpine temperatures reach a high of -10 °C. Ridge wind southwest 25 km/h gusting to 50 km/h. Freezing level at valley bottom.
Sunday
Cloudy with snowfall, 5-15 cm of accumulation. Alpine temperatures reach a high of -9 °C. Ridge wind southwest 20 km/h gusting to 50 km/h. Freezing level: 700 meters.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Wind Slabs
Recent new snow has been redistributed by southwest switching to northeast winds. Wind slabs may exist on all aspects in exposed areas and will have likely decreased in reactivity with recent cold temperatures.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Two weak layers consisting of a crust with small facets above buried between 50 and 180cm deep, have been responsible for several large avalanches in the past two weeks. This problem seems to be more of an issue west of the Sea to Sky highway corridor. This layer is of greatest concern with large triggers, such as a cornice fall, or by first triggering a smaller avalanche that could step down to this interface.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 24th, 2023 4:00PM
